The present invention relates to a device for an automatic interchange of grippers to robots or manipulating devices.
Devices for coupling grippers to robots or manipulating devices of the aforementioned type generally include a mounting or receiving body or member, and an interchanging plate carrying a gripper removably-connectable to the mounting body.
A complete automation during the manufacture and assembling of articles of manufacture has, until now, only been possible in mass production. Various article or workpiece dimensions or their differing geometries have required an exchange of grippers or gripper jaws carrying the tools.
A fully automatic programmable tool exchange or tool plate exchange has been known in machine tools or treatment centers.
It has not been possible to provide an automatic and programmable gripper exchange in the field of robot technology without overcoming considerable difficulties requiring complex solutions.
An automatic manufacturing operation for producing a limited number of a line of products has been possible only when the machine tool and the manipulating device or robot were adjusted to a new workpiece corresponding to a new line of products to be manufactured.
A gripper-interchange system has been known, in which receiving or engaging forces of the interchanging plate are generated by electromagnets mounted in the receiving body. Although the principle of operation of this system is very simple, the system has substantial disadvantages. During the manufacture of iron-containing articles or, in the case of iron-containing chips, this system cannot be employed because there is a danger of contamination of this system. In case of power failure the interchanging plate can suddenly drop. The entire weight of the system in comparison with its holding force is large.
Another known device of this type operates with compressed air and included laterally extended pressure air cylinders which effect locking of the interchanging plate carrying the gripper to the mounting plate connected to a robot. A bulky, heavy and complex intermediate member for receiving an also complicated gripper-receiving or interchanging plate is arranged between these two cylinders. The heavy weight of this conventional device substantially limits the abilities of the device to receive heavy workpieces. If rather heavy articles are to be produced another adjacent large robot must be employed to treat the articles. Dimensions of this device, however, considerably limit its application. Furthermore, since the conventional device requires special treatment procedures during its manufacturing, it has been very costly. In addition, an extremely costly interchanging plate is required for each gripper.
Yet another known device for coupling the gripper-holding interchanging plate with a mounting or receiving body includes a short or steep cone with tension belts pulled into another cone. This device has been known in the field of machine tools, and, more particularly, in milling machines. The coupling and locking of the gripper-holding plate with the mounting body, and therefore a safety, are ensured even in the case of power failure. With milling machines, a sufficient space is available along the machine so that the weight of the pulling motor does not present any disturbance. However, because of its limited volume, this system is not suitable for application in industrial robots. The weight of this system reduces a possible weight of workpieces being treated, and the overall length of the system requires a specific robot head. In as much as a special robot head must be provided with an electric motor or compressed air motor, the system has not been and could not be universally utilized.